Should DH's job come ahead of mine because he earns more?

This Is totally unreasonable of your DH. Standard hours are not changeable or negotiable. I assume this would not have happened in your last role.

Typically I’d agree with your DH (as long as he’s being respectful and courteous about it) but when I saw you had a £60k job it gave me pause, because I don’t think that an employer who’s paying you almost double the national average salary would be happy with the attitude that you need to be the flexible one because your husband’s job always takes priority. After all, in many households £60k is what the main breadwinner is earning. So I think you’re stuck between a rock and a hard place because if he carries on like this, your boss will have something to say eventually.

So what does your work say when you dont do your office days?

Have you explained to your husband you have contracted days and what does he say?

Why cant you both go into office - what are your childcare arrangements?

Well that’s not ok. There’s a massive difference between you fitting your job around his and you putting your whole job at risk. He’s completely disregarding you and your needs.

The family as a whole needs to come first. Not his job and not your job. He’s behaving like a twat. He needs to put in place a system that he can use if his work changes. So a nanny or call on family to help. I would be very firm on this. He has caused this problem and he needs to sort it out

This is unbalanced because you chose to reduce your income by half so you had less stress and had more time with the kids, that means DH’s job does need to come first because he can’t just choose to reduce his income.
You decided your job was less important when you took a 50% pay cut.

No, he doesn’t get to treat you as if no arrangement you make matters at all because of his salary. Fuck that. The expectation is that he treats you as a partner and an equal, is respectful and courteous- or what’s the point?

Remind him hes the one going back on what you agreed and get childcare sorted. Hes deliberately sabotaging your career if he wasn't like this before and it will only get worse IMO.

My instinct says that the job that supports the family should be protected but every member of the family should feel valued and everyone should work to this. A joint agreement is needed to allocate tasks efficiently, equitably and with the wellbeing of everyone first in mind.
What does this look like? If one income can be lived on and both parents work, then other tasks needs to be outsourced? A good conversation about what tasks in the house each liven do easily, prefers or wants to do. Fair distribution of income in terms of access to money. A common goal in spending, saving and plans. But you need to be on the same page for this.

You seem to have taken a pay cut and you have a lot of responsibility - was the pay cut worth the benefits of a new role? How long do you plan to do this for? What is the effect on your pension etc?

It’s solvable with a shared goal.

I can see why this has annoyed you.

Maybe the bigger question is why, considering you have a big household income, you don't have sufficient childcare to both be in the office?

Just imagine you both work in a similar place doing a similar job but he gets paid 3x more than you.
Neither of you get paid when not at work.

Which one of you would it be more sensible to take the day off if an errands needed doing or your kids need something?

So yes, his job is inherently more important because it brings in so much more money. Also you agreed to change jobs in order to be flexible. If you don't like being that flexible you may as well go back to the other work where you haven't the option of so much flexibility.

How much is he financially contributing to the household and how much are you contributing? Whoever contributes more has a more important job. It’s not rocket science.

Not sure why people try and engage in intellectual contortionism over the subject of main breadwinners etc. Unless you can run your household without cold hard cash, then more money means more important job.

Yes sorry I think if he earns more and you took a pay cut for work life balance you have to be more flexible.
Obviously things like office days need to be arranged in advance and stuck to so he cant just change his mind on that.

Surprised by this. Yeah his job takes priority but that doesn't mean he gets to do the kind of things that would get you fired which, where I work, not meeting contracted office days, would. My job takes priority over my husbands because of a similar salary split but we still plan so we can both meet our minimum obligations.

So what does he say when you say you aren't meeting the minimum office days?

The issue is you took the cut to be available. I do get that shouldn't mean that it is ALWAYS you but you do need to have a proper conversation about expectations.

If DH took a 50% paycut for a more relaxed job and the agreement was that he picks up more of the day to day running around then yes, I would expect that he generally fits his career around mine.

Can you support the family on your salary?

Money is the bottom line here.

You took a voluntary huge pay cut. Your workplace is flexible. You should be flexing around his schedule. You got what you wanted with a much less stressful job and better work life balance. And now you want him to flex around your job. I think you're moving the goalposts here

The real issue is not the finances, it's that you feel taken for granted. It's not unreasonable for you to want him to have some regard for you and show you some consideration.

Yeah, I’m on his side here. You need to be able to pay the bills.

Also, is it £20k vs £60k or £60k vs £180k

I think it’s somewhere in between. He should be flexible where he can, but if not possible then yes, it probably should be on you given the active step of changing jobs to be able to take the slack.

His job is more important to your household finances, obviously.

And you purposefully got a job that had a better life balance - which I completely agree with you doing (I have done similar) but the reality is that you pick up the slack.

However, if you think he’s now taking the piss and checking more and more out of family life, you need to speak to him and sort that out.